Rubber diaphragm and method of making the same



March 15, 1938. I J. T. CLARK I RUBBER DIAPHRAGM AND METHOD OF MAKING THE SAME Filed March 26, 1937 Patented Mar. 15, 1938 UNITED STATES RUBBER. DIAPHRAGM AND METHOD 'OF MAKING THE SAME John Clark, Cicero. Ill.

Application March 26, 1937, Serial No. 1335279 4 Claims.

This invention relates to improvements in pessary or rubber diaphragm and method of making the same. The invention is particularly applicable to hemispherical diaphragms of the occlusive type in which a spiral metal spring is enclosed in the thickened peripheral marginal portion of the diaphragm.

Among the features of my invention,-is the making of such a device in which the spring is completely enclosed in rubber and in which the rubber entirely impregnates and fills the inside of the spring.

Another feature of my invention is the making of such a device particularly by molding the rubher, thus forming a more effective union between the diaphragm proper and its periphery.

By the use of molding, the manufacture is greatly facilitated and the completed article is a great improvement over the older devices made by dipping and forming processes.

Other features and advantages of my inven tion will appear more fully as I proceed with my specification.

In that form of the device embodying the features of my invention shown in the accompanying drawing,--

Fig. l is a top plan view; Fig. 2 is a similar enlarged fragmentary view showing a portion broken away; a

Fig. 3 is a vertical sectional view taken through the mold;

Fig. 4 is a similar enlarged fragmentary view;

Fig. 5 is a view showing one of the final steps in the making of the device;

Fig. 6 is an enlarged fragmentary view of a portion of the device showing the same before the last step in the manufacture; and

Fig. '7 is a similar view showing the device aite completion of the last step. e

As shown in the drawing, the mold includes the lower convex member Ill and the upper concave member 1|, slightly separated to form a hemispherical space I2 therebetween for the reception of the rubber to make the diaphragm proper. v

At the periphery, the upper mold part II is provided with a relatively large annular cavity l3, and the lower mold part III is provided with a cooperating relatively small annular cavity I4 to hold the spiral spring I5.

- In the making of the device, the mold parts are put together, as shown in Figs. 3 and 4, with the spring 15 in place. Rubber is put in the space 12 and also in the space 13, and the mold 5 is suitably filled with rubber in a well known REISSUED FEB 6-1 manner and vulcanized, as is well known in the rubber art. The result of these steps in the manufacture is to produce a partially completed diaphragm, as shown in Fig. 6, in which l6 indicates the diaphragm proper of thin rubber with 5 the mold part II), it will be seen that the rubber 15 on the bottom of the spring is very thin. In fact, there .may be places where the spring shows through on the bottom. In Fig. 6, I have indicated this very thin layer of rubber by reference numeral l9. It will be seen also that the an- 0 nular cavity l3 in the mold part II is considerably wider than the cavity I4 in the mold part It. Consequently, the thickened rubber cover over the top of the spring I 5 terminates in the two shoulders 20 and 2|, as shown in Fig. 6. 25

After completion of the partially formed device, as shown in Fig. 6, I dip the lower half of the spring in liquid rubber or latex 22 until it is covered with rubber 23, as shown in Fig. '7. This rubber is allowed to harden, or may be suitably vulcanized. Beforethis dipping, the shoulders 20 and 2| and the lower portion of the spring is preferably coated with liquid cement. The dipping is preferably continued until the covering 23 on the under side of the spring is substantially 5 the same thickness as the covering 23 above the spring; that is, until the shoulders 20 and 2| are obliterated. In dipping the device in the liquid latex, as shown in Fig. 5, it is preferably held at a slight slant and then rolled around so that the 40 dipping will be progressive rather than simultaneous throughout the entire circumference to prevent the undue trapping of air.

While I have shown and described certain embodiments of my invention, it is to be understood 45 A that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my inten- 50 tion to claim all novelty inherent in my invention as broadly as permissible, in view of the prior art. What I claim as new and desire to secure by Letters Patent is:

1. The method of making a substantially hemlspherical rubber diaphragm with a thickened pe ripheral marginal portion having a resilient reiniorcing member embedded therein, consisting 01' providing a mold with a space for the diaphragm proper and a peripheral cavity for the reinforcing member, placing the reinforcing member in said cavity resting on the bottom thereof, filling said mold to form the diaphragm proper and cover the reinforcing member except the bottom thereof, and then applying rubber to the bottom of said reinforcing member, by dipping, to completely cover the same.

2. The method of making a substantially hemispherical rubber diaphragm with a thickened peripheral marginal portion having a spiral spring embedded therein, consisting of providing a mold with a space for the diaphragm proper and a peripheral cavity for the spiral spring, placing the spiral spring in said cavity resting on the bottom thereof, filling said mold to form thediaphragm proper and cover the spiral spring except the bottom thereof, and then applying rubber to the bottom of said spiral spring, by dipping, to completely cover the same.

The method of making a mhstaniially hemispherical rubber diaphragm with a thickened pe ripheral marginal portion consisting of first, molding the diaphragm proper and the upper part of the thickened marginal portion, said upper part terminating in shoulders, and then completing the thickened marginal portion by dipping until the lower part of the thickened mar- 5:181 portion is built up even with the shoul- 4. The method of making a substantially hemispherical rubber diaphragm with a thickened peripheral marginal portion having a resilient reiniorcing member embedded therein, .consisting of first molding the diaphragm proper and the upper part of the thickened marginal portion to cover the top of the reinforcing member, said .upper part terminating in shoulders, and then completing the thickened marginal portion by dipping until the lower part of the thickened marginal portion is built up even with the shoultiers and the bottom of the reinforcing member covered.

JOHN '1'. CLARK. 

